Throughout history, social movements have seen mostly small advances, but there’s also been a few huge, colossal, gigantic steps forward — and here’s one that most people have never even heard about.

In 1971, a gay man was allowed to emigrate to the US from Cuba. Madison. In March of 1975, Wisconsin passed a civil rights bill. In 1984, the European Parliament adopted a resolution in favor of civil rights for LGBT people. In 1985, William Hurt won an Oscar for playing a gay man in Kiss of the Spider Woman.

A few of the milestones predicted better things to come: In March of 1972, the American Bar Association recommended that consensual sex between same-sex couples be decriminalized; it would take another 30 years for the Supreme Court to finally make that happen. ACT UP staged its first major action in 1987, provoking government officials to stop dragging their feet on HIV/AIDS.

But one amazing milestone is the first time a government official knowingly awarded a marriage license to a same-sex couple.

The official’s name was Clela Rorex, and she never meant to make history. She simply ran for clerk of Boulder, Colorado because she was tired of being told that only a man could win. She might not have been elected, except that college-age students had recently been granted the right to vote, and they voted heavily for Clela.

Only a few weeks into the job in 1975, two men walked into her office and requested a marriage license. She had never known any openly gay people, and had never given any thought to the idea that they might want to marry. But now she had a choice to make.

It took a few days of deliberations and close inspection of the law. Finally, Clela decided, she couldn’t think of any reason to deny them the license. So she did.

A handful of additional couples came by the office when they heard what was happening. One of them was bi-national, and used the license to apply for citizenship — that was denied, with the federal government sending them a letter referring to them both as “faggots.”

The general consensus in Boulder, in Colorado and around the country was that what Clela was doing was unacceptable. Amid a firestorm of criticism, one man even came by the office trying the marry his horse. It was a crackpot political stunt, of course, and Clela wouldn’t dignify the request beyond pointing out that the horse was too young to marry.

Eventually, the state forced her to stop issuing the licenses, and eventually she was forced to resign. She would have been recalled if she hadn’t, and at least resigning allowed the Democrats to name a replacement.

Thirty years later, tides had changed and public opinion had shifted to realize that what Clela did was the right thing to do. It took decades for her to finally be vindicated. But it was worth the wait.